Muac z-score device and methods of use thereof

ABSTRACT

The present disclosure is directed towards an electronic device, method of using a device, and a method of making a device for estimating the nutritional status in an individual of any age or weight. The electronic device measures the circumference of a body part of an individual and determines a standard score value for the individual based upon a designated age and gender to estimate the nutritional status of the individual. The method includes measuring the circumference of a body part of an individual using the electronic device and determining a standard score value from the device to estimate the nutritional status of the individual.

BACKGROUND

The World Health Organization has determined that anthropometry, the comparative measurement and study of the human body, reflects both nutritional and health status and that it is predictive of performance, health, survival, and the risk of disease. Anthropometric measurements can also be used to assess the need of an individual for special services such as nutritional rehabilitation and support, or to assess the response of a patient to an intervention. The middle-upper arm circumference (MUAC) of an individual is an anthropometric measurement known to be a reliable indicator of skeletal protein and subcutaneous fat, both important determinants of malnutrition. In some studies, MUAC has been found to be better at predicting death in children than any other anthropometric indicator. The MUAC measurement, which is taken on the left arm, at the mid-point between the tip of the shoulder (i.e., the upper edge of the posterior border of the acromion process) and the tip of the elbow (i.e., the olecranon process), has been widely adopted as a favored anthropometric technique. MUAC measurement has been vigorously promoted as the preferred anthropometric technique by the World Health Organization (WHO), United Nations Children's Fund (UNICEF), and many governmental and private health organizations throughout the world. In addition to its value as a nutritional status assessment tool, MUAC measurement is favored because it requires no expensive equipment or extensive training, is portable, easy to use and widely applicable. MUAC measurement can be taken regardless of the age or health status of the individual or the ability to stand, sit or walk. MUAC measurements can be taken on even the most debilitated individuals.

Currently MUAC is widely used by international agencies to evaluate the nutritional status of children in medically underserved areas such as developing nations. More recently, The Academy of Nutrition and Dietetics and the American Society for Parenteral and Enteral Nutrition drafted a consensus statement with recommendations for diagnosing and documenting pediatric malnutrition in the United States, (Becker et al. J Acad. Nutr. Diet. 2014; 114: 1988-2000). MUAC was among the indicators of malnutrition the consensus panel recommended for evaluation. The panel proposed that “MUAC measurements should be part of the full anthropometric assessment in all patients, and are particularly important in those whose weight may be affected by lower-extremity edema, ascites, or steroids, as weight trends alone are unreliable related to fluid status. When serial z scores are unavailable, serial MUAC measurements can be used to monitor changes in body composition using the child as his or her own control. MUAC has been indicated as a more sensitive prognostic indicator for mortality than weight-for-height parameters in malnourished pediatric patients.” These entities advise that, “trained individuals consistently perform these measurements for best long-term comparison of data.” They further explicitly recommend that “z score, decline in z score, and negative z score” be used to classify and document pediatric malnutrition.

The World Health Organization has developed Child Growth Standards, comprising a set of population norms for malnutrition based on MUAC measurements for boys and girls from age 3 months to 5 years. While MUAC measurements can be taken with any measuring tape marked in millimeters, nutritional status is determined by referencing a set of norms that establish the measurements associated with various stages of malnutrition. Typically, these norms reflect a standard reference value that represents the central tendency (i.e., the mean or median) arm measurement for a nutritionally healthy child of a given age in the reference population. Variance from the reference mean value is measured in standard deviations. How far (i.e. how many standard deviations) away a child's measurement is from this population mean is represented by a number or standard score commonly known as the z-score. Thus, the reference mean value is assigned a z-score of 0. The various stages of malnutrition (specifically under nutrition) are defined by negative standard deviations from the mean, or negative z-scores. However, the World Health Organization (WHO) has developed a single child growth threshold for the identification of severe acute malnutrition in infants and children that is not based on z-score. It has issued the MUAC measuring tape that incorporates color bands which discriminate between severe acute malnutrition, moderate acute malnutrition, at risk for acute malnutrition, and normal in children up to 5 years of age. Importantly, the WHO MUAC tape reflects singular categorical color-banding thresholds for all children irrespective of age, such that reliability suffers considerably at the extremes of age.

While the use of z-scores in association with MUAC measurements has proven more reliable than the use of percentile deviations from a reference value, MUAC measurements for a population rarely produce a normal distribution represented by a bell-shaped curve. This is particularly true where there are instances of extreme differences in individual measurements within the population. For example, in some populations, the dataset of MUAC population values is skewed, or distributed asymmetrically, resulting in a curve that is shifted to the right or left of the reference value. Though skewness will influence z-scores, this is not accounted for if the MUAC data from the reference population are presumed to fit a normal standard distribution. Additionally, the peak of the distribution curve for the MUAC measurements in a reference population may be taller, sharper, or flatter than a standard bell curve. This so-called excess kurtosis occurs where more of the variability in the measurements is due to a few extreme differences from the reference value, rather than numerous modest differences. On the resulting curve, the probability of intermediate values is less likely and the central and extreme values are more likely. In settings of skewness or excessive kurtosis, the data must first be transformed to generate a near-normal distribution, then curve fit to define the mathematical function that best fits the data (traditionally a cubic spline), and finally back-transformed to arrive at the specific (i.e., lambda, mu, and sigma (“LMS”)) values from which the z-score can be calculated.

Currently available MUAC tapes endorsed by the WHO provide MUAC in millimeters and offer a single color scheme to indicate the risk for malnutrition. However, these tapes apply the same threshold values to all children irrespective of age. As discussed above, this singular threshold loses accuracy as children age. Consequently, application of the currently available MUAC tapes does not facilitate longitudinal assessments of children. Further, the currently available MUAC tapes provide no frame of reference for the distance from the mean that these children fall relative to children their own age. Additionally, the existing MUAC tapes do not take into consideration children over the age of 5 years, adolescents, and adults whose nutritional status may also be at risk. Finally, the existing MUAC tapes do not address malnutrition that contributes to overweight and obesity (overnutrition). Such individuals typically do not exhibit the loss of upper arm muscle mass associated with malnourishment and so are overlooked by current MUAC screening devices and methods. However, protein-calorie malnutrition is known to contribute to obesity, and such individuals may require nutrition support to address malnutrition. The current MUAC device does not provide a means to categorize such overweight and obese individuals according to their nutritional status and risk for malnutrition.

What is needed in the art is an improved device and method for estimating the nutritional status of an individual at any age, including an infant, child, adolescent, or adult without regard to variability in the dataset for the reference population. Further, what is needed is such an improved device and method that can be used in a population of all ages and across a broad weight range. Further, what is needed is such an improved device and method that can determine nutritional status (as defined by z-score) in a single step, without the need to identify the correct reference chart and determine a range from the chart. Further, what is needed is a method of making such a device based on creating a scale of numbers, indicia, or symbols that correspond to the circumference of the middle upper arm, middle upper thigh, chest or other circumference and its standard score for individuals of various ages and weights.

SUMMARY OF THE INVENTION

The present disclosure overcomes the problems inherent in the prior art and provides devices and methods for easily estimating the nutritional status of an individual who may be an infant, child, adolescent or adult, and who may be of low or normal weight, overweight, or obese. Additionally, a method for designing such a device for estimating nutritional status is disclosed.

The device and method of the present disclosure incorporate the measurement of circumference as a surrogate for body habitus (“physique”) into a nutritional estimation strategy that performs robustly independently of age, weight, gender, and geographic origin over a large range of variables, whether varying independently or together. The present disclosure was developed on the premise that nutritional status for all age, weight, and population groups can be accurately assessed by use of measurements of the circumference of a body part's z-score. The body part can be selected from the middle upper arm, middle thigh, chest, or abdomen. The present disclosure advantageously simplifies the measurement process so that a single measurement of a body part can be made and the z-score range for the nutritional indicator for a particular age and gender within a given population can be simultaneously read directly from the device (as opposed to consulting one or more separate tables or charts to see how the measurement translates into a standard score indicating deviations from the mean).

The device can be designed to reflect z-score ranges calculated from lambda, mu, and sigma (LMS) values that derive from population data that has been transformed and smoothed as described above. Alternatively, the demarcated ranges can reflect the centiles for the raw untransformed data that correspond to selected z-scores as defined in standard normal probability tables. A reference to z-score ranges in this application considers either process.

Preferably, the device consists of one or more strips, each containing a scale of indicia for use in measuring the circumference of a body part of an individual each strip also containing a scale of indicia showing the standard scores indicating standard deviations above and below the nutritional norm that are associated with the measurement indicia. In one embodiment, the device consists of indicia for obtaining a numerical measurement of the middle-upper arm circumference as well as a plurality of rows or bands of indicia showing standard scores indicating the norm as well as standard deviations above and below the nutritional norm associated with the measurement indicia for designated ages or age ranges. The numerical measurement indicia are arranged in side-by-side correspondence with the age-specific standard score bands. In one embodiment, the indicia indicating the standard deviations also include demarcations that indicate the quarter z-scores, e.g., 0, 0.25, 0.5, 0.75, 1, etc. In another embodiment, the indicia indicating the standard deviations also include demarcations indicating the tenth z-scores, e.g., 0, 0.1, 0.2, 0.3, etc. In another embodiment, the indicia indicating the standard deviations also include demarcations indicating the hundredth z-scores, e.g., 0, 0.01, 0.02, 0.03, etc. It is foreseen that the indicia indicating the standard deviations may also include indicia that indicate the centiles that correspond to a specified standard deviation range. Preferably the strips include numerical indicia designating the age or age range associated with the respective bands of scales of standard scores. Preferably the strips are constructed so that they include an indicator or cursor for indicating the circumference measurement and corresponding standard score. Preferably the indicia showing the scale of standard scores are colored so that a standard score for one age or age range is the same color as the same standard score for another age or age range. It can be appreciated that the indicia showing standard scores will be different depending on the age and population group for which the strip is designed. In one embodiment the device consists of a plurality of strips, each including indicia for measurement and display of standard scores for a particular gender, age, ages, or age range and population. In other embodiments, the circumference of another body part will be used. Preferred body parts include the middle thigh, abdomen, and chest.

The one or more strips that are part of the device can be made from any flexible material that is able to be imprinted and used in measuring the circumference of the middle-upper arm of an individual. Preferably, the strips will also be non-deformable such that any scale of indicia printed thereon will not be deformed (i.e., it will not be distorted) during use, shipping, or storage of the strips. Preferably, the material for the strips can be selected from, but is not limited to, ribbon, plastic compositions, waxed paper, plastic-coated paper, laminated paper, paper, metal, silicon, natural and man-made fibers, and the like. In a most preferred embodiment the one or more strips are made of commonly available fibers, such as paper laminated with a plastic coating.

Preferably, scales of indicia are printed on the strip to indicate linear measurement and standard scores indicating standard deviations from the nutritional norm. The printing can be on either one or both sides of the strip. The indicia can include numbers, letters, symbols, colors, or other indicia. In one preferred embodiment, numbers are printed with a single device corresponding with the linear measurement scale. The circumference of the body part can be shown in any scale of measurement such as inches or centimeters, but preferably is shown in centimeters and millimeters. In the preferred embodiment, color bands are printed on the strip corresponding with the scales of standard scores. The scales of standard scores are aligned with the linear measurement scale to indicate how many standard deviations from normal nutritional status are indicated by a given corresponding linear measurement.

In an embodiment where the device comprises multiple strips, it is sometimes preferred that both sides of the strips are imprinted with indicia to reduce the number of strips required. In one embodiment, the device consists of one or more strips with the measurement scale indicia and corresponding standard score scale indicia for one gender printed on one side, and the measurement scale indicia standard score scale indicia for the other gender printed on the opposite side. In another embodiment, the device consists of strips with the measurement scale indicia and standard score scale indicia for one group of ages or age ranges on one side, and the measurement scale indicia standard score scale indicia for another group of ages or age ranges on the opposite side. In still another embodiment, the device consists of strips with measurement scale indicia and standard score indicia for one population group on one side and measurement scale indicia and standard score scale indicia for another population group on the opposite side. In still another embodiment, the standard score scale indicia reflect data from a designated age or age range in a specific population. As can be appreciated, the device can be arranged in a multitude of different ways depending on the population being measured.

In one embodiment the strips include a measurement portion and a fastener portion. Preferably the fastener portion is located at one end of the tape. Preferably the fastener portion includes an indicator for use in reading the numerical measurement scale and corresponding standard score scale indicia. Preferably the fastener portion includes a slot for receiving the free end of the tape and serving as an indicator. Preferably the fastener portion includes indicia indicating age or age ranges associated with the bands of standard score scale of indicia. Where the standard score scale indicia are color-coded, the tape preferably includes a color key for indicating the standard deviation associated with the corresponding standard score scale indicia. Where the standard score scale indicia are color-coded, the tape may also include a color key for indicating a numerical score or z-score associated with each of the standard score scale indicia.

In one alternate embodiment, an electronic measurement device is employed having measurement means for obtaining a body part circumference measurement, such as a tape, cord, laser or any other suitable means. Additional components of the electronic measurement device that are in wired or wireless communication with the measurement means include various hardware components, such as a processing unit, data storage or system memory including a computer readable medium storing computer executable instructions for executing a program that measures the circumference of the body part and provides a user interface for entering selected parameters regarding the individual to be measured. Such parameters may include one or more of age, gender, demographic information, and any other information relevant to determination of the z-score. Additional hardware components may also include a visual display device, which may include alpha numeric, color, sound or video capability for display of the z-score.

A method for determining the nutritional status of an individual is also disclosed. The method comprises measuring the circumference of a body part of an individual and reading the corresponding standard score from the standard score scale on the tape. Where an electronic measurement device is employed, the method comprises using the user interface to enter selected parameters regarding the individual to be measured, measuring the circumference of a body part of an individual, and reading the z-score from the visual display device. Preferred body parts include the middle upper arm, the middle thigh, the abdomen, and the chest. In a preferred embodiment, the method generally includes the steps of determining the midpoint of the upper arm of an individual and measuring the circumference of the middle-upper arm at the midpoint thereof. In a preferred embodiment, the midpoint of the upper arm is the midpoint between the tip of the shoulder and the tip of the elbow. In another preferred embodiment, the midpoint of the upper arm is the midpoint between the olecranon process and the acromion.

Preferably, the method utilizes a device of the present disclosure. In an embodiment of the method where a device comprising multiple strips is used, each strip is imprinted with a scale of measurement indicia for girth measurement and a plurality of scales of standard score indicia for indicating standard scores associated with nutritional norms for preselected ages or age ranges. The imprinted indicia may also take into account gender, and/or population group. In this embodiment, the method includes measuring the circumference of a body part of a member of the corresponding gender, age and population group by identifying the corresponding measurement scale indicium with the measurement indicator and reading the corresponding standard score from the standard score scale associated with the age of the individual. In an embodiment of the method where the device consists of strips imprinted on both sides, one side of the strip is used for measuring the body part's circumference and reading the corresponding age or age-range specific standard score on one side for a member of the corresponding gender and/or population group, and the other side is used for measuring and reading the score for a member of a different age, gender, or population group. In this embodiment, each of the circumference measurements will correspond to a different scale of indicia on each respective side of the strip. In an embodiment where the device comprises an electronic measurement device, the processing unit executes instructions, such as program modules, with reference to stored data to determine the z-score with reference to z-score ranges calculated as previously described. Preferred body parts include the middle-upper arm, middle thigh, abdomen, and chest.

A method for making the device of the present disclosure is also disclosed. The method includes the steps of obtaining one or more datasets correlating measurements of the body part's circumference with nutritional status at various ages using a mathematical equation to create one or more scales based on the one or more datasets that correlate the circumference measurement to nutritional norms according to age, and printing one or more strips with the scales and standard score indicia to create a device for estimating nutritional status. Preferably, this method results in the device of the present disclosure that is used according to the method of using the device disclosed herein. Where the method involves use of an electronic measurement device, the method includes the steps of obtaining one or more datasets correlating measurements of the body part's circumference with nutritional status at various ages using a mathematical equation to create one or more scales based on the one or more datasets that correlate the circumferential measurement to nutritional norms according to age, providing the scales that correlated the measurements to nutritional norms in the form of computer-readable data accessible to the processing unit, and including such scales in a device that measures the circumference of a body part. Preferred body parts include the middle-upper arm, middle thigh, abdomen, and chest.

In use, electronic devices in accordance with the present disclosure would measure circumference by recording the distance traveled by a ball, roller, laser, or the like, as it was placed on the skin of the body part and moved about the circumference of the body part. In another embodiment of an electronic device, the device includes a measuring tape that can be wrapped about the circumference of the body part to be measured. The measuring tape is then drawn up against the body part by means of a retraction mechanism which can be manual, automated, or even electronically controlled. The measurement is then recorded by conventional means and correlated with the scales in order to determine nutritional status.

The method generally includes obtaining one or more datasets and examining circumference measurements of a body part against the median circumference measurements of nutritionally healthy individuals with the same circumference measurement values. From this, a mathematical model, preferably, a mathematical model with one or more empirically determined parameters or “constants”, is developed which predicts nutritional status. Preferred body parts include the middle-upper arm, middle thigh, abdomen, and chest.

The device and methods of the present disclosure are preferably made for infants, children, adolescents, adults, males, and females as well as a wide variety of population groups. Strips designed for members of one or more combinations of these groups would simply use different dataset(s) to determine a different scale of numbers and/or indicia corresponding to circumference measurements. Further, the device and methods of the present disclosure can be customized to fit different populations of adults and children depending on different factors such as, but not limited to, geographic origin, age, ethnic background, and other social factors.

In preferred forms, the present disclosure provides a device for estimating nutritional status of an individual of any age or weight wherein the device generally includes a flexible elongate strip having a front side and a back side. Preferably, each of the front side and the back side includes two scales of indicia thereon. Preferably, a first scale of indicia on the front side provides a first value when the strip is used to measure the circumference of a body part, and a second scale of indicia on the front side provides a nutritional health standard score second value corresponding to the first value. A third scale of indicia on the back side provides a third value when the strip is used to measure the circumference of a body part, and a fourth scale of indicia on the back side provides a nutritional health standard score fourth value corresponding to the third value. The second value may take into account age, gender or a designated population group, and the fourth value may take into account a different age, gender or designated population group. In preferred forms, the first and third scales of indicia for the front side and the back side are in 1 cm and 1 mm gradations or in 1 cm and 0.5 cm and 1 mm gradations. One particularly preferred scale for measuring the circumference or girth of the middle of the upper arm (the midpoint of the humerus) has 1 mm, 0.5 cm, and 1 cm gradations on the scale of indicia from 9.0 cm to 57.0 cm. It is understood that if the scale begins at 9 cm, a small number of individuals will fall outside of the gradations. However, the scale can be started at a lower number, e.g. 8, cm, 7, cm, 6 cm, etc. Additionally, in electronic versions, the scale can begin at any number greater than zero. Preferably, the indicia on each scale of indicia are in a form selected from the group consisting of numbers, letters, symbols, colors, and combinations thereof. One particularly preferred scale of indicia for measuring the standard score corresponding to the scale of indicia for measuring girth has gradations corresponding to standard scores of greater than −1, less than −1, less than −2 and less than −3 and less than 1, greater than 1, greater than 2 and greater than 3. Preferred body parts include the middle-upper arm, middle thigh, abdomen, and chest.

Another preferred device for estimating nutritional status of an individual of any age or weight wherein the device generally includes a plurality of flexible elongate strips, each having a front side and a back side. Preferably, each of the front side and the back side includes two scales of indicia thereon. Preferably, a first scale of indicia on the front side provides a first value when the strip is used to measure the circumference of a body part, and a second scale of indicia on the front side provides a nutritional health standard score second value corresponding to the first value. A third scale of indicia on the back side provides a third value when the strip is used to measure the circumference of the body part, and a fourth scale of indicia on the back side provides a nutritional health standard score fourth value corresponding to the third value. The second value may take into account age, gender or a designated population group, and the fourth value may take into account a different age, gender or designated population group. In preferred forms, the first and third scales of indicia for the front side and the back side are in 1 cm and 1 mm gradations or in 1 cm and 0.5 cm and 1 mm gradations. One particularly preferred scale for measuring the circumference or girth of the middle of the upper arm (the midpoint of the humerus) has 1 mm, 0.5 cm, and 1 cm gradations on the scale of indicia from 9.0 cm to 57.0 cm. Preferably, the indicia on each scale of indicia are in a form selected from the group consisting of numbers, letters, symbols, colors, and combinations thereof. One particularly preferred scale for measuring the standard score corresponding to the scale for measuring girth has gradations corresponding to standard scores of greater than −1, less than −1, less than −2 and less than −3 and less than 1, greater than 1, greater than 2 and greater than 3. Each side of each strip may be customized to fit a different age group, gender or population or combination thereof. Groups of strips may be customized to fit different age and gender groups within a particular population. Preferred body parts include the middle-upper arm, middle thigh, abdomen, and chest.

The present application may be described in the context of computer-executable instructions, such as program modules, being executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, and so forth, which perform particular tasks or implement particular abstract data types.

The present disclosure provides for a suitable computing and networking environment that may be used to implement various aspects of the present disclosure. The computing and networking environment generally includes a general purpose computing device, although it is contemplated that the networking environment may include other computing systems, such as personal computers, server computers, hand-held or laptop devices, tablet devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronic devices, network PCs, minicomputers, mainframe computers, digital signal processors, state machines, logic circuitries, distributed computing environments that include any of the above computing systems or devices, and the like.

Components of the computer may include various hardware components, such as a processing unit, a data storage (e.g., a system memory), and a system bus that couples various system components of the computer to the processing unit. The system bus may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. For example, such architectures may include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus also known as Mezzanine bus.

The computer may further include a variety of computer-readable media that includes removable/non-removable media and volatile/nonvolatile media, but excludes transitory propagated signals. Computer-readable media may also include computer storage media and communication media. Computer storage media includes removable/non-removable media and volatile/nonvolatile media implemented in any method or technology for storage of information, such as computer-readable instructions, data structures, program modules or other data, such as RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to store the desired information/data and which may be accessed by the computer. Communication media includes computer-readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. For example, communication media may include wired media such as a wired network or direct-wired connection and wireless media such as acoustic, RF, infrared, and/or other wireless media, or some combination thereof. Computer-readable media may be embodied as a computer program product, such as software stored on computer storage media.

The data storage or system memory includes computer storage media in the form of volatile/nonvolatile memory such as read only memory (ROM) and random access memory (RAM). A basic input/output system (BIOS), containing the basic routines that help to transfer information between elements within the computer (e.g., during start-up) is typically stored in ROM. RAM typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit. For example, in one embodiment, data storage holds an operating system, application programs, and other program modules and program data.

Data storage may also include other removable/non-removable, volatile/nonvolatile computer storage media. For example, data storage may be: a hard disk drive that reads from or writes to non-removable, nonvolatile magnetic media; a magnetic disk drive that reads from or writes to a removable, nonvolatile magnetic disk; and/or an optical disk drive that reads from or writes to a removable, nonvolatile optical disk such as a CD-ROM or other optical media. Other removable/non-removable, volatile/nonvolatile computer storage media may include magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM, and the like. The drives and their associated computer storage media, described above provide storage of computer-readable instructions, data structures, program modules and other data for the computer.

A user may enter commands and information through a user interface or other input devices such as a tablet, electronic digitizer, a microphone, keyboard, and/or pointing device, commonly referred to as mouse, trackball or touch pad. Other input devices may include a joystick, game pad, satellite dish, scanner, or the like. Additionally, voice inputs, gesture inputs (e.g., via hands or fingers), or other natural user interfaces may also be used with the appropriate input devices, such as a microphone, camera, tablet, touch pad, glove, or other sensor. These and other input devices are often connected to the processing unit through a user interface that is coupled to the system bus, but may be connected by other interface and bus structures, such as a parallel port, game port or a universal serial bus (USB). A monitor or other type of display device is also connected to the system bus via an interface, such as a video interface. The monitor may also be integrated with a touch-screen panel or the like.

The computer may operate in a networked or cloud-computing environment using logical connections of a network interface or adapter to one or more remote devices, such as a remote computer. The remote computer may be a personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computer 300. The logical connections include one or more local area networks (LAN) and one or more wide area networks (WAN), but may also include other networks. Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet.

When used in a networked or cloud-computing environment, the computer may be connected to a public and/or private network through the network interface or adapter. In such embodiments, a modem or other means for establishing communications over the network is connected to the system bus via the network interface or adapter or other appropriate mechanism. A wireless networking component including an interface and antenna may be coupled through a suitable device such as an access point or peer computer to a network. In a networked environment, program modules depicted relative to the computer, or portions thereof, may be stored in the remote memory storage device.

The present disclosure also provides a method of estimating nutritional status of an individual of any age. The method generally includes the steps of measuring the circumference of a body part of an individual using a flexible elongate strip having a first scale of measurement indicia thereon and a second scale of indicia to provide a nutritional health standard score corresponding to the circumference for a selected age or age range, gender or designated population or combination thereof. In another form of the method, a flexible elongate strip is selected from a plurality of flexible elongate strips, each having a first scale of measurement indicia thereon and a second scale of indicia to provide a nutritional health standard score corresponding to the circumference of a body part for a selected age or age range, gender or designated population or combination thereof. A user selects a flexible elongate strip having a scale of indicia to provide a nutritional health standard score corresponding to the characteristics of the individual to be measured. In preferred forms, the scale of indicia for girth measurements are in 1 cm and 1 mm gradations or in 1 cm and 0.5 cm and 1 mm gradations. One particularly preferred scale for measuring the circumference or girth of the middle of the upper arm (the midpoint of the humerus) has 1 mm, 0.5 cm, and 1 cm gradations on the scale of indicia from 9.0 cm to 57.0 cm. Further, in this embodiment, the scale for measuring the standard score corresponding to the scale for measuring girth has gradations corresponding to standard scores of greater than −1, less than −1, less than −2 and less than −3 and less than 1, greater than 1, greater than 2 and greater than 3. Preferred body parts include the middle-upper arm, middle thigh, abdomen, and chest.

Advantageously, the methods of the present disclosure can also be adapted to estimate weight based on a variety of other measurements, and preferably other measurements of circumference or girth. In preferred forms, such other measurements include, but are not limited to the middle thigh, chest, and abdomen. When the middle thigh is used to estimate weight, the middle thigh circumference is preferably measured at the midpoint between the inguinal crease and the proximal border of the patella with the measurement being taken perpendicular to the long axis of the thigh. When the chest circumference is used to estimate weight, the circumference is preferably measured at the end of exhalation with the individual's arms extended outward and the tape or measurement positioned under the axilla, around wrapping around the chest at the level of the nipples. When abdominal circumference is used to estimate weight, the circumference is measured with the tape or measurement positioned in a horizontal plane at the level of the ilium wrapping just over the umbilicus. In each measurement, the measuring tape or device is preferably pulled snugly or contacted with the skin without compressing the skin.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

FIG. 1 is an illustration of a strip of one embodiment of the device of the present disclosure (MUAC z-score tape) for use on children aged 2 months to 47 months including standard score indicia that represent standard score ranges calculated from lambda, mu, and sigma (LMS) values that derive from population data that has been transformed and smoothed. The strip illustrated in FIG. 1 has been cut into two sections so that it fits onto a single page;

FIG. 2 is an illustration of another strip of one embodiment of the device for use on ages 4 years to 18 years including standard score indicia that represent standard score ranges calculated from lambda, mu, and sigma (LMS) values that derive from population data that has been transformed and smoothed. The strip illustrated in FIG. 2 has been cut into two sections so that it fits onto a single page;

FIG. 3 is an illustration of a strip of a second embodiment of the device for use on children aged 2 months to 47 months wherein the strip displays z-score ranges calculated to reflect the centiles for the raw untransformed data that correspond to selected z-scores as defined in standard normal probability tables. The strip illustrated in FIG. 3 has been cut into two sections so that it fits onto a single page:

FIG. 4 is an illustration of a strip of a second embodiment of the device for use on children aged 4 to 18 years wherein the strip displays z-score ranges calculated to reflect the centiles for the raw untransformed data that correspond to selected z-scores as defined in standard normal probability table. The strip illustrated in FIG. 4 has been cut into three sections so that it fits onto a single page; and

FIG. 5 is a diagrammatic representation of an electronic embodiment of the device.

DETAILED DESCRIPTION

In one preferred embodiment of the present disclosure, illustrated in FIGS. 1 and 2, the device 1 comprises a plurality of elongate flexible strips 10, 11. The strips are of similar construction and unless otherwise indicated, each reference numeral applies to both strips. The strips 10 and 11 each have a respective first side 20 and an opposing second side 30, each of which includes imprinted indicia. The strips also each have a respective first end 40 and a second end 50. The first end 40 includes a fastener member 60, which may or may not be of unitary construction with the strip. The fastener 60 is sized and shaped to extend laterally beyond the sides of the strip sufficient to include an opening 61 such as a slit or slot 61. The slot 61 is positioned orthogonal to the strip and is sized for sliding reception of the second end 50 of the strip, thereby forming the strip 10 into a band for encircling a body part of an individual. The second end of each strip may be shaped at the sides to form a slightly narrower tip 51 for ease of insertion into the slot 61. The fastener members 60 and the respective strips 10 and 11 may be of unitary construction, or the fasteners may be formed separately and attached to form the first end 40 of the respective strip. Preferred body parts include the middle-upper arm, middle thigh, abdomen, and chest.

The first and second sides 20, 30 of the strips are each imprinted with two types of scales of indicia. A first scale of linear measurement indicia 70 includes a linear measurement scale marked with 1 mm, 0.5 mm and 1 cm gradations for measuring the circumference of a body part of an individual. The gradations may extend from 0 cm to 100 cm depending on the anticipated girth of body part of the individuals to be measured. Strip 10 is designed for use in individuals aged 2 months to 36 months, and includes gradations from 8 cm to 36 cm. Strip 11 is designed for individuals aged 4 years to 18 years and includes gradations from 9 cm to 57 cm. Preferred body parts include the middle-upper arm, middle thigh, abdomen, and chest. With specific reference to FIGS. 1-4, the strips and scales thereon are particularly adapted for instances when the body part is the middle upper arm.

Scales of standard score indicia 80 corresponding to preselected ages or age ranges are arranged in stacked relation above and/or below the first scale of indicia 70. The standard score indicia 80 can represent standard score ranges calculated from lambda, mu, and sigma (LMS) values that derive from population data that has been transformed and smoothed as previously described. Alternatively, the demarcated ranges can reflect the centiles for the raw untransformed data that correspond to selected standard scores as defined in standard normal probability tables. The standard score indicia scales 80 include a plurality of age or age range-specific scales of indicia, each of which indicates the range of linear measurements corresponding to a respective number of standard deviations from the mean measurement associated with nutritional status. For example, on strip 11 a first standard score indicia scale 81 represents standard scores for children aged 2 months. A second standard score indicia scale 82 represents standard scores for children aged 3 months. A third standard score indicia scale 83 represents standard scores for children aged 4 months. A fourth standard score indicia scale 84 represents standard scores for children aged 5 months. A fifth standard score indicia scale 85 represents standard scores for children aged 6 to 11 months. A sixth standard score indicia scale 86 represents standard scores for children aged 12 to 23 months. A seventh standard score indicia scale 87 represents standard scores for children aged 24 to 35 months. A second standard score indicia scale 88 represents standard scores for children aged 36 to 47 months.

The scales of standard score indicia each include groups of different indicia, each of which groups indicates the range of linear measurements corresponding to the norm and a respective number of standard deviations from the mean measurement associated with normal nutritional status. For example, a standard score of 1 for nutritional health is indicated by the reference numeral 90. A standard score greater than −1 for nutritional health (between the mean and 1 standard deviation below the mean) is indicated by the reference numeral 91. A standard score less than −1 (between 1 and 2 standard deviations below the mean) is indicated by the reference numeral 92. A standard score less than −2 (between 2 and 3 standard deviations below the mean) is indicated by the reference numeral 93. A standard score less than −3 (greater than 3 standard deviations below the mean) is indicated by the reference numeral 94. A standard score less than 1 (between the mean and 1 standard deviation above the mean) is indicated by the reference numeral 95. A standard score greater than 1 (between 1 and 2 standard deviations above the mean) is indicated by the reference numeral 96. A standard score greater than 2 (between 2 and 3 standard deviations above the mean) is indicated by the reverence numeral 97. A standard score greater than 3 (greater than 3 standard deviations above the mean) is indicated by the reference numeral 98.

An age key 100 is provided adjacent the slot 61 and is positioned so that each standard score indicia scale aligns with the corresponding age indicium when the circumference measurement of the body part is taken. An additional age key 101 is provided adjacent the ends of the standard score indicia scales at the lower end of the measurement indicia scale. A standard score or z-score key 102 may be provided in any open location, preferably between the fastener member 60 and the commencement of the scales 70 and 80. Preferred body parts include the middle-upper arm, middle thigh, abdomen, and chest. With specific reference to FIGS. 1-4, the scales thereon are particularly adapted for circumferential measurements of the middle-upper arm.

In use, an investigator selects a strip 10 designed to reflect data for the individual to be screened, e.g., according to age or age range, gender, or population group. Next, the investigator determines the body part they are going to measure and measures the circumference thereof as described herein. Preferred body parts include the middle-upper arm, middle thigh, abdomen, and chest. In one embodiment, the measurement taken is the midpoint of the upper arm, that is, the midpoint between the tip of the shoulder and the tip of the elbow of the individual to be measured. The investigator may wrap the strip 10 around the arm at the midpoint and then insert the second end of the strip into the slot 61 in the fastener portion 60 to encircle the arm. Alternatively, the investigator may insert the second end of the strip into the slot 61 to form a circle, which is then slid up the arm to its midpoint. When the strip has been positioned to encircle the midpoint of the upper arm, the investigator pulls on the free end of the strip to snug it against the arm of the individual. The margin of the slot overlying the indicia serves as an indicator or cursor to assist the investigator in reading the numeric measurement and standard score from the respective scales imprinted on the strip. In this manner, an investigator can simultaneously obtain both a middle-upper arm circumference measurement as well as the individual's standard or z-score for nutritional status, without the need to perform any further calculation or reference any table or chart.

A second preferred embodiment of the present disclosure is illustrated in FIGS. 3 and 4 to display z-score ranges calculated to reflect the centiles for the raw untransformed data that correspond to selected z-scores as defined in standard normal probability tables. FIGS. 3 and 4 depict parts in common with FIGS. 1 and 2 designated by corresponding reference numerals with the prime symbol (′). Additionally, FIGS. 3 and 4 include demarcations 104 within each standard score. These demarcations provide mathematical quartile distributions within each standard score. It is understood that these quartiles can be evenly or unevenly distributed. Further, although mathematical quartiles are shown in the figure, it is understood that those of skill in the art would also be able to construct and use other even and uneven distributions within each standard score. For example, 1/10^(th), or 1/100^(th) standard score value gradations could also be used.

FIG. 5 illustrates an example of a suitable computing and networking environment 300 that may be used to implement various aspects of the present disclosure described in FIGS. 1-4. As illustrated, the computing and networking environment 300 includes a general purpose computing device 300, although it is contemplated that the networking environment 300 may include other computing systems, such as personal computers, server computers, hand-held or laptop devices, tablet devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronic devices, network PCs, minicomputers, mainframe computers, digital signal processors, state machines, logic circuitries, distributed computing environments that include any of the above computing systems or devices, and the like.

Components of the computer 300 may include various hardware components, such as a processing unit 302, a data storage 304 (e.g., a system memory), and a system bus 306 that couples various system components of the computer 300 to the processing unit 302. The system bus 306 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. For example, such architectures may include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus also known as Mezzanine bus.

The computer 300 may further include a variety of computer-readable media 308 that includes removable/non-removable media and volatile/nonvolatile media, but excludes transitory propagated signals. Computer-readable media 308 may also include computer storage media and communication media. Computer storage media includes removable/non-removable media and volatile/nonvolatile media implemented in any method or technology for storage of information, such as computer-readable instructions, data structures, program modules or other data, such as RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to store the desired information/data and which may be accessed by the computer 300. Communication media includes computer-readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. For example, communication media may include wired media such as a wired network or direct-wired connection and wireless media such as acoustic, RF, infrared, and/or other wireless media, or some combination thereof. Computer-readable media may be embodied as a computer program product, such as software stored on computer storage media.

The data storage or system memory 304 includes computer storage media in the form of volatile/nonvolatile memory such as read only memory (ROM) and random access memory (RAM). A basic input/output system (BIOS), containing the basic routines that help to transfer information between elements within the computer 300 (e.g., during start-up) is typically stored in ROM. RAM typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit 302. For example, in one embodiment, data storage 304 holds an operating system, application programs, and other program modules and program data.

Data storage 304 may also include other removable/non-removable, volatile/nonvolatile computer storage media. For example, data storage 304 may be: a hard disk drive that reads from or writes to non-removable, nonvolatile magnetic media; a magnetic disk drive that reads from or writes to a removable, nonvolatile magnetic disk: and/or an optical disk drive that reads from or writes to a removable, nonvolatile optical disk such as a CD-ROM or other optical media. Other removable/non-removable, volatile/nonvolatile computer storage media may include magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM, and the like. The drives and their associated computer storage media, described above and illustrated in FIG. 3, provide storage of computer-readable instructions, data structures, program modules and other data for the computer 300.

A user may enter commands and information through a user interface 310 or other input devices such as a tablet, electronic digitizer, a microphone, keyboard, and/or pointing device, commonly referred to as mouse, trackball or touch pad. Other input devices may include a joystick, game pad, satellite dish, scanner, or the like. Additionally, voice inputs, gesture inputs (e.g., via hands or fingers), or other natural user interfaces may also be used with the appropriate input devices, such as a microphone, camera, tablet, touch pad, glove, or other sensor. These and other input devices are often connected to the processing unit 302 through a user interface 310 that is coupled to the system bus 306, but may be connected by other interface and bus structures, such as a parallel port, game port or a universal serial bus (USB). A monitor 312 or other type of display device is also connected to the system bus 306 via an interface, such as a video interface. The monitor 312 may also be integrated with a touch-screen panel or the like.

The computer 300 may operate in a networked or cloud-computing environment using logical connections of a network interface or adapter 314 to one or more remote devices, such as a remote computer. The remote computer may be a personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computer 300. The logical connections depicted in FIG. 3 include one or more local area networks (LAN) and one or more wide area networks (WAN), but may also include other networks. Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets and the Internet.

When used in a networked or cloud-computing environment, the computer 300 may be connected to a public and/or private network through the network interface or adapter 314. In such embodiments, a modem or other means for establishing communications over the network is connected to the system bus 306 via the network interface or adapter 314 or other appropriate mechanism. A wireless networking component including an interface and antenna may be coupled through a suitable device such as an access point or peer computer to a network. In a networked environment, program modules depicted relative to the computer 300, or portions thereof, may be stored in the remote memory storage device.

As can be appreciated, the figures and description above, are particularly well-suited for use with manual measurements using strips as described for the middle upper arm circumference. It is understood that the same data used to generate the standard scores can be provided in an electronic measurement device as well as for other body parts as described above. In use, electronic devices in accordance with the present disclosure would measure circumference by recording the distance traveled by a ball, roller, laser, or the like, as it was placed on the skin of the body part and moved about the circumference of the body part. In another embodiment of an electronic device, the device includes a measuring tape that can be wrapped about the circumference of the body part to be measured. The measuring tape is then drawn up against the body part by means of a retraction mechanism which can be manual, automated, or even electronically controlled. The measurement is then recorded by the device using conventional means and correlated with the scales in order to automatically determine nutritional status.

Definitions

A “child” or “children” for purposes of the present disclosure include any person from birth to 18 years of age. The present disclosure includes a preferred embodiment where the device of the present disclosure is suitable for children from 2 months to 18 years of age.

A “measurement” for purposes of the present disclosure refers to the use of a device to determine a value. The value can be circumference or girth, etc.

“Indicia” for purposes of the present disclosure refers to letters, numbers, symbols, colors, and patterns.

“Mean” and “median” for purposes of the present disclosure refer to a reference value that represents the central tendency. These terms are used interchangeably unless otherwise indicated.

“MUAC Z-score tape” for purposes of the present disclosure refers to one embodiment of the device of the present disclosure wherein the middle upper arm circumference is the body part measured.

A “scale” for purposes of the present disclosure refers to a set of values, numbers, or indicia that represent values used to obtain the estimated weight or dose. Alternately, a scale can be a physical weight measuring machine, depending on the context in which the word “scale” is used.

A “standard score” or “z-score” for purposes of the present disclosure refers to the number of standard deviations the body part circumference measurement is above or below a standard reference body part circumference measurement for a reference population that is associated with nutritional health, with a standard score of 0.0 indicating the norm, negative standard scores indicating below −1.0 and positive standard scores above 1.0 indicating scores outside the body part circumference measurement associated with nutritional health.

A “strip”, for purposes of the present disclosure, refers to a rectangular shaped segment of material that is longer than it is wide. A strip in the context of the present disclosure is part of the device of the present disclosure.

EXAMPLES

The following examples are provided for illustrative purposes only. Nothing contained herein shall be construed as a limitation of the scope of the present disclosure.

Example 1

This example illustrates a method of using the device of the present disclosure to estimate nutritional status using the middle upper arm circumference.

Materials and Methods

An embodiment of the device of the present disclosure incorporating one strip that will be printed on both sides is used, wherein one side had a scale for girth and a scale for standard scores for females and the other side had a scale for girth and a scale for standard scores for males.

The side of the strip printed with a scale for female girth is used to measure the middle-upper arm circumference of a female. This value is recorded, along with the corresponding standard score which is read from the strip. The side of the strip printed with a scale for male girth is used to measure the middle-upper arm circumference of a male. This value is recorded, along with the corresponding standard score which is read from the strip. The score of the female is used to inform the decision to institute nutritional support for treatment of malnutrition. The score of the male is used to inform the decision to conduct further testing to determine whether obesity-based malnutrition may be present.

Results and Discussion

Because the standard score for the female is less than −2, the female is undernourished. Because the standard score for the male is greater than 3, the male is also at risk for malnutrition based on overweight or obesity. Because obesity can be an indicator for malnutrition, the male is referred for further evaluation.

Example 2

This example illustrates a method of using centiles corresponding to a specified z-score range as derived from the standard probability table to demarcate the percent of the reference population that falls within the MUAC z-score tape zones.

Methods

For a reference population wherein the MUAC values are not normally distributed (e.g. skewness >0.5, kurtosis >1.0) and there has been no transformation to symmetry or smoothing of the data, the MUAC z-score tape zones can be demarcated by the centiles that correspond to a specified z-score range as derived from the standard normal probability table (provided below in Table 1). For example; a z-score range from −1.50 to −1.75 would be represented by the MUAC values for the lower 6.68% and 4.01% of the population, respectively.

The scales of standard score indicia each include groups of different indicia, each of which groups indicates the range of linear measurements corresponding to the norm and a respective number of standard deviations from the median measurement associated with normal nutritional status. Referring now to FIGS. 3 and 4, for example, a standard score of 1 for nutritional health corresponding to the 84.13 centile is indicated by the reference numeral 90′. A standard score greater than −1 for nutritional health (between the 15.87 and 50.00 centile) is indicated by the reference numeral 91′. A standard score less than −1 (between the 2.28 and 15.87 centiles) is indicated by the reference numeral 92′. A standard score less than −2 (between the 1.30 and 2.28 centiles) is indicated by the reference numeral 93′. A standard score less than −3 (less than the 1.00 centile) is indicated by the reference numeral 94′. A standard score less than 1 (between the 50.00 and 84.13 centile) is indicated by the reference numeral 95′. A standard score greater than 1 (between the 84.13 and 97.72 centiles) is indicated by the reference numeral 96′. A standard score greater than 2 (between the 97.72 and 99.87 centiles) is indicated by the reference numeral 97′. A standard score greater than 3 (greater than 99.87 centile) is indicated by the reference numeral 98′. Quarter z-scores are also shown on FIGS. 3 and 4 by the reference numeral 104′.

TABLE 1 Standard Normal Probabilities z .00 .01 .02 .03 .04 .05 .06 .07 .08 .09 −3.4 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.03% 0.02% −3.3 0.05% 0.05% 0.05% 0.04% 0.04% 0.04% 0.04% 0.04% 0.04% 0.03% −3.2 0.07% 0.07% 0.06% 0.06% 0.06% 0.06% 0.06% 0.05% 0.05% 0.05% −3.1 0.10% 0.09% 0.09% 0.09% 0.08% 0.08% 0.08% 0.08% 0.07% 0.07% −3.0 0.13% 0.13% 0.13% 0.12% 0.12% 0.11% 0.11% 0.11% 0.10% 0.10% −2.9 0.19% 0.18% 0.18% 0.17% 0.16% 0.16% 0.15% 0.15% 0.14% 0.14% −2.8 0.26% 0.25% 0.24% 0.23% 0.23% 0.22% 0.21% 0.21% 0.20% 0.19% −2.7 0.35% 0.34% 0.33% 0.32% 0.31% 0.30% 0.29% 0.28% 0.27% 0.26% −2.6 0.47% 0.45% 0.44% 0.43% 0.41% 0.40% 0.39% 0.38% 0.37% 0.36% −2.5 0.62% 0.60% 0.59% 0.57% 0.55% 0.54% 0.52% 0.51% 0.49% 0.48% −2.4 0.82% 0.80% 0.78% 0.75% 0.73% 0.71% 0.69% 0.68% 0.66% 0.64% −2.3 1.07% 1.04% 1.02% 0.99% 0.96% 6.94% 0.91% 0.89% 0.87% 0.84% −2.2 1.39% 1.36% 1.32% 1.29% 1.25% 1.22% 1.19% 1.16% 1.13% 1.10% −2.1 1.79% 1.74% 1.70% 1.66% 1.62% 1.58% 1.54% 1.50% 1.46% 1.43% −2.0 2.28% 2.22% 2.17% 2.12% 2.07% 2.02% 1.97% 1.92% 1.88% 1.83% −1.9 2.87% 2.81% 2.74% 2.68% 2.62% 2.56% 2.50% 2.44% 2.39% 2.33% −1.8 3.59% 3.51% 3.44% 3.36% 3.29% 3.22% 3.14% 3.07% 3.01% 2.94% −1.7 4.46% 4.36% 4.27% 4.18% 4.09% 4.01% 3.92% 3.84% 3.75% 3.67% −1.6 5.48% 5.37% 5.26% 5.16% 5.05% 4.95% 4.85% 4.75% 4.65% 4.55% −1.5 6.68% 6.55% 6.43% 6.30% 6.18% 6.06% 5.94% 5.82% 5.71% 5.59% −1.4 8.08% 7.93% 7.78% 7.64% 7.49% 7.35% 7.21% 7.08% 0.94% 6.81% −1.3 9.68% 9.51% 9.34% 9.18% 9.01% 8.85% 8.69% 8.53% 8.38% 8.23% −1.2 11.51% 11.31% 11.12% 10.93% 10.75% 10.56% 10.38% 10.20% 10.03% 9.85% −1.1 13.57% 13.35% 13.14% 12.92% 12.71% 12.51% 12.30% 12.10% 11.90% 11.70% −1.0 15.87% 15.62% 15.39% 15.15% 14.92% 14.69% 14.46% 14.23% 14.01% 13.79% −0.9 18.41% 18.14% 17.88% 17.62% 17.36% 17.11% 16.85% 16.60% 16.35% 16.11% −0.8 21.19% 20.90% 20.61% 20.33% 20.05% 19.77% 19.49% 19.22% 18.94% 18.67% −0.7 24.20% 23.89% 23.58% 23.27% 22.96% 22.66% 22.36% 22.06% 21.77% 21.48% −0.6 27.43% 27.09% 26.76% 26.43% 26.11% 25.78% 25.46% 25.14% 24.83% 24.51% −0.5 30.85% 30.50% 30.15% 29.81% 29.46% 29.12% 28.77% 28.43% 28.10% 27.76% −0.4 34.46% 34.09% 33.72% 33.36% 33.00% 32.64% 32.28% 31.92% 31.56% 31.21% −0.3 38.21% 37.83% 37.45% 37.07% 36.69% 36.32% 35.94% 35.57% 35.20% 34.83% −0.2 42.07% 41.68% 41.29% 40.90% 40.52% 40.13% 39.74% 39.36% 38.97% 38.59% −0.1 46.02% 45.62% 45.22% 44.83% 44.43% 44.04% 43.64% 43.25% 42.86% 42.47% −0.0 50.00% 49.60% 49.20% 48.80% 48.40% 48.01% 47.61% 47.21% 46.81% 46.41% 0.0 50.00% 50.40% 50.80% 51.20% 51.60% 51.99% 52.39% 52.79% 53.19% 53.59% 0.1 53.98% 54.38% 54.78% 55.17% 55.57% 55.96% 56.36% 56.75% 57.14% 57.53% 0.2 57.93% 58.32% 58.71% 59.10% 59.48% 59.87% 60.26% 60.64% 61.03% 61.41% 0.3 61.79% 62.17% 62.55% 62.93% 63.31% 63.68% 64.06% 64.43% 64.80% 65.17% 0.4 65.54% 65.91% 66.28% 66.64% 67.00% 67.36% 67.72% 68.08% 68.44% 68.79% 0.5 69.15% 69.50% 69.85% 70.19% 70.54% 70.88% 71.23% 71.57% 71.90% 72.24% 0.6 72.57% 72.91% 73.24% 73.57% 73.89% 74.22% 74.54% 74.86% 75.17% 75.49% 0.7 75.80% 76.11% 76.42% 76.73% 77.04% 77.34% 77.64% 77.94% 78.23% 78.52% 0.8 78.81% 79.10% 79.39% 79.67% 79.95% 80.23% 80.51% 80.78% 81.06% 81.33% 0.9 81.59% 81.86% 82.12% 82.38% 82.64% 82.89% 83.15% 83.40% 83.65% 83.89% 1.0 84.13% 84.38% 84.61% 84.85% 85.08% 85.31% 85.54% 85.77% 85.99% 86.21% 1.1 86.43% 86.65% 86.86% 87.08% 87.29% 87.49% 87.70% 87.90% 88.10% 88.30% 1.2 88.49% 88.69% 88.88% 89.07% 89.25% 89.44% 89.62% 89.80% 89.97% 90.15% 1.3 90.32% 90.49% 90.66% 90.82% 90.99% 91.15% 91.31% 91.47% 91.62% 91.77% 1.4 91.92% 92.07% 92.22% 92.36% 92.51% 92.65% 92.79% 92.92% 93.06% 93.19% 1.5 93.32% 93.45% 93.57% 93.70% 93.82% 93.94% 94.06% 94.18% 94.29% 94.41% 1.6 94.52% 94.63% 94.74% 94.84% 94.95% 95.05% 95.15% 95.25% 95.35% 95.45% 1.7 95.54% 95.64% 95.73% 95.82% 95.91% 95.99% 96.08% 96.16% 96.25% 96.33% 1.8 96.41% 96.49% 96.56% 96.64% 96.71% 96.78% 96.86% 96.93% 96.99% 97.06% 1.9 97.13% 97.19% 97.26% 97.32% 97.38% 97.44% 97.50% 97.56% 97.61% 97.67% 2.0 97.72% 97.78% 97.83% 97.88% 97.93% 97.98% 98.03% 98.08% 98.12% 98.17% 2.1 98.21% 98.26% 98.30% 98.34% 98.38% 98.42% 98.46% 98.50% 98.54% 98.57% 2.2 98.61% 98.64% 98.68% 98.13% 98.75% 98.78% 98.81% 98.84% 98.87% 98.90% 2.3 98.93% 98.96% 98.98% 99.01% 99.04% 99.06% 99.09% 99.11% 99.13% 99.16% 2.4 99.18% 99.20% 99.22% 99.25% 99.27% 99.29% 99.31% 99.32% 99.34% 99.36% 2.5 99.38% 99.40% 99.41% 99.43% 99.45% 99.46% 99.48% 99.49% 99.51% 99.52% 2.6 99.53% 99.55% 99.56% 99.57% 99.59% 99.60% 99.61% 99.62% 99.63% 99.64% 2.7 99.65% 99.66% 99.67% 99.68% 99.69% 99.70% 99.71% 99.72% 99.73% 99.74% 2.8 99.74% 99.75% 99.76% 99.77% 99.77% 99.78% 99.79% 99.79% 99.80% 99.81% 2.9 99.81% 99.82% 99.82% 99.83% 99.84% 99.84% 99.85% 99.85% 99.86% 99.86% 3.0 99.87% 99.87% 99.87% 99.88% 99.88% 99.89% 99.89% 99.89% 99.90% 99.90% 3.1 99.90% 99.91% 99.91% 99.91% 99.92% 99.92% 99.92% 99.92% 99.93% 99.93% 3.2 99.93% 99.93% 99.94% 99.94% 99.94% 99.94% 99.94% 99.95% 99.95% 99.95% 3.3 99.95% 99.95% 99.95% 99.96% 99.96% 99.96% 99.96% 99.96% 99.96% 99.97% 3.4 99.97% 99.97% 99.97% 99.97% 99.97% 99.97% 99.97% 99.97% 99.97% 99.98%

Conclusion

Demarcation of the centiles that correspond to specified z-score range in this manner provides a z-score tape that includes additional necessary information for use with reference populations where the MUAC measurement values are not normally distributed.

Middle-upper arm circumference in conjunction with data on established standard scores for nutritional health in a reference population based on age, gender and ethnicity address a critical medical need in settings where populations must be screened with portable devices that are simple to use, require minimal training and provide results that are visually displayed without the need for further calculation or interpretation from reference tables or charts. To date, no single previous device or method has provided accurate estimates of nutritional status across a broad range of ages, and populations for both genders. The MUAC Z-score device and method attempts to address limitations inherent in the existing nutritional status estimation strategies. It expands the age range of individuals to which a single nutritional status estimation method can be applied and expands the screenable population to include individuals who are overweight or obese but may suffer from malnutrition.

Example 3

This example illustrates a method of using LMS corresponding to a specified z-score range as derived from the standard probability table to demarcate the percent of the reference population that falls within the MUAC z-score tape zones.

Anthropometric data for model development were obtained from the Centers for Disease Control and Prevention (CDC) National Health and Nutrition Examination Survey (NHANES). Data from 1999-2012 were downloaded and datasets for children 2 months through 18 years of age extracted into a separate database. Incomplete datasets and those missing the relevant variables were excluded. MUAC outliers that might be the result of measurement error were identified by application of the modified Thompson tan test. Data were segregated by gender and mean (x) and standard deviation (σ) MUAC were calculated at each month of age. The absolute deviation for each data point (δi) was determined according to δi=|x|−x|. The modified Thompson tau value was calculated according to τ=[tα/2*(n−1)]/[√n*√(n−2+tα/22)] where n is the number of data points and tα/2 is the student's t value based on a highly conservative a value of 0.001 with n−2 degrees of freedom. The individual sample with the largest Si value was rejected when δi>τ*σ. Subsequently x and σ were recalculated and recursive elimination was used to remove each successive maximum Si value until no additional outliers were identified (i.e. δi≤r*σ). To avoid introducing imprecision with smaller than recommended sample sizes, selected age groups were pooled in a similar fashion to the groupings used by the CDC in the construction of their 2000 growth charts. Data for children 1 year of age and over were pooled in 6 month intervals. Data from children 2-11 months of age were retained in 10 distinct age groups and weighted to limit bias in fitting toward the older age groups. Though the sample sizes were smaller for this infant population, estimates of skewness and kurtosis confirmed a near normal distribution. Independently collected data from 2 different U.S. studies were used for validation. These investigations were reviewed and approved by the Institutional Review Board at Children's Mercy Hospital. Comparisons were also made to earlier published MUAC centiles from the 1971-1974 and 1988-1994 surveys. Gender-specific growth curves were created using the Lambda Mu Sigma method described by Cole and Green, and executed with LMSchartmaker Pro v2.54 (Harlow Pronting Limited, Tyne & Wear, UK). The distribution of MUAC values were summarized for each age group using age-specific Box-Cox power transformation of skewness (L), median (M), and coefficient of variation (S). This method transforms the anthropometric data so that they are approximately normally distributed and generates age-specific estimates of LMS as cubic smoothing splines by nonlinear regression. Maximum penalized likelihood estimation was used to optimize the effective degrees of freedom (edf) for M followed by L and then S. Goodness-of-fit was assessed by examining 1) plots of the fitted centiles overlaid on the empirical centiles, 2) the detrended quantile-quantile (Q-Q) plots of the z-scores with their corresponding worm plots, 3) the Q statistics for L, M, S. and kurtosis, and 4) the mean and standard deviation of z-scores at each age group. The newly created LMS values were applied to data from a population of children wherein MUAC was obtained as part of a larger anthropometric survey. For each child, gender- and age-specific z-score was calculated according to zi=(((xi/M){circumflex over ( )}L)−1)/(LS). Where zi represents the individual z-score, xi the individual MUAC value, and LMS the lambda, mu, and sigma values, respectively. For cases where L=0, z-score was calculated according to zi=ln(xi/M)/S. The data were stratified into groups of sufficient sample size and the mean and standard deviation of z-scores at each age group was examined as described above. The distribution of weight-for-age z-scores was also examined for concordance with MUAC z-scores. Finally, the growth curves were compared with previously published data to examine and trends in U.S. norms over the last 4 decades. All comparisons were performed in SPSS v23 (IBM, Armonk, N.Y.). Results are provided in Table 2. The values within Table 2 are well adapted for use within a database, and especially within a database used or accessed by an electric measurement device wherein the device measures a desired part, accesses the database contained therein, and provides the user with the z-score and/or weight.

TABLE 2 z-score calculation where L ≠ 0 z_(i) = (((x_(i)/M){circumflex over ( )}L) − 1)/(LS). z-score calculation where L = 0 z_(i) = ln(x_(i)/M)/S. Males Females Age (mos) L M S L M S 2 1.162 13.680 0.083 −0.096 13.276 0.084 3 1.025 14.081 0.081 −0.119 13.635 0.083 4 0.899 14.419 0.080 −0.142 13.979 0.083 5 0.782 14.688 0.079 −0.166 14.279 0.082 6 0.675 14.903 0.078 −0.192 14.526 0.081 7 0.575 15.078 0.077 −0.223 14.722 0.081 8 0.482 15.218 0.076 −0.257 14.879 0.081 9 0.394 15.323 0.075 −0.295 15.009 0.081 10 0.310 15.401 0.075 −0.335 15.120 0.080 11 0.228 15.464 0.075 −0.377 15.219 0.080 12 0.148 15.524 0.075 −0.419 15.308 0.080 13 0.069 15.581 0.074 −0.460 15.390 0.080 14 −0.010 15.637 0.074 −0.500 15.467 0.080 15 −0.087 15.691 0.074 −0.537 15.538 0.080 16 −0.164 15.741 0.074 −0.572 15.603 0.080 17 −0.240 15.786 0.074 −0.605 15.662 0.080 18 −0.315 15.828 0.073 −0.635 15.716 0.080 19 −0.390 15.864 0.073 −0.664 15.767 0.080 20 −0.465 15.897 0.073 −0.691 15.813 0.080 21 −0.538 15.928 0.073 −0.716 15.856 0.080 22 −0.612 15.958 0.073 −0.739 15.896 0.080 23 −0.684 15.988 0.073 −0.760 15.933 0.081 24 −0.756 16.019 0.073 −0.781 15.969 0.081 25 −0.828 16.051 0.073 −0.802 16.005 0.081 26 −0.899 16.086 0.073 −0.823 16.040 0.081 27 −0.969 16.121 0.073 −0.844 16.075 0.081 28 −1.038 16.158 0.073 −0.865 16.110 0.081 29 −1.105 16.196 0.074 −0.886 16.145 0.081 30 −1.171 16.234 0.074 −0.907 16.181 0.081 31 −1.236 16.273 0.075 −0.931 16.221 0.081 32 −1.298 16.313 0.075 −0.955 16.262 0.082 33 −1.359 16.354 0.076 −0.980 16.304 0.082 34 −1.419 16.397 0.076 −1.006 16.347 0.082 35 −1.477 16.441 0.077 −1.033 16.392 0.082 36 −1.532 16.487 0.078 −1.061 16.438 0.083 37 −1.586 16.534 0.078 −1.091 16.486 0.083 38 −1.639 16.583 0.079 −1.121 16.535 0.083 39 −1.689 16.634 0.080 −1.151 16.586 0.083 40 −1.737 16.684 0.081 −1.183 16.637 0.084 41 −1.784 16.736 0.081 −1.215 16.690 0.084 42 −1.828 16.787 0.082 −1.247 16.743 0.085 43 −1.871 16.838 0.083 −1.280 16.797 0.085 44 −1.912 16.889 0.084 −1.313 16.851 0.086 45 −1.950 16.940 0.085 −1.346 16.905 0.086 46 −1.987 16.990 0.086 −1.379 16.960 0.087 47 −2.022 17.039 0.087 −1.411 17.014 0.087 48 −2.055 17.088 0.088 −1.444 17.068 0.088 49 −2.086 17.137 0.089 −1.475 17.121 0.088 50 −2.115 17.185 0.089 −1.506 17.173 0.089 51 −2.142 17.233 0.090 −1.537 17.225 0.089 52 −2.168 17.280 0.091 −1.567 17.277 0.090 53 −2.191 17.328 0.092 −1.596 17.328 0.091 54 −2.213 17.377 0.093 −1.625 17.379 0.091 55 −2.233 17.425 0.094 −1.653 17.429 0.092 56 −2.251 17.474 0.095 −1.681 17.480 0.093 57 −2.268 17.524 0.096 −1.708 17.530 0.093 58 −2.282 17.574 0.097 −1.735 17.581 0.094 59 −2.294 17.626 0.098 −1.761 17.632 0.095 60 −2.305 17.677 0.099 −1.786 17.683 0.096 61 −2.314 17.730 0.100 −1.811 17.735 0.096 62 −2.321 17.784 0.101 −1.835 17.788 0.097 63 −2.326 17.838 0.102 −1.858 17.841 0.098 64 −2.329 17.893 0.103 −1.881 17.896 0.099 65 −2.330 17.949 0.104 −1.903 17.951 0.100 66 −2.330 18.005 0.105 −1.924 18.009 0.101 67 −2.328 18.062 0.106 −1.944 18.068 0.102 68 −2.324 18.120 0.107 −1.963 18.130 0.103 69 −2.319 18.179 0.108 −1.981 18.193 0.104 70 −2.312 18.239 0.109 −1.998 18.257 0.105 71 −2.304 18.300 0.110 −2.013 18.323 0.106 72 −2.294 18.363 0.112 −2.026 18.391 0.107 73 −2.284 18.427 0.113 −2.038 18.460 0.108 74 −2.271 18.493 0.114 −2.048 18.531 0.109 75 −2.258 18.561 0.115 −2.056 18.604 0.111 76 −2.243 18.631 0.116 −2.062 18.679 0.112 77 −2.227 18.702 0.117 −2.066 18.756 0.113 78 −2.210 18.775 0.119 −2.069 18.835 0.114 79 −2.192 18.849 0.120 −2.068 18.917 0.116 80 −2.173 18.925 0.121 −2.066 19.002 0.117 81 −2.152 19.002 0.122 −2.061 19.088 0.118 82 −2.131 19.080 0.123 −2.054 19.177 0.120 83 −2.109 19.160 0.124 −2.044 19.267 0.121 84 −2.085 19.240 0.125 −2.032 19.358 0.123 85 −2.061 19.322 0.126 −2.017 19.450 0.124 86 −2.036 19.404 0.127 −1.999 19.543 0.125 87 −2.010 19.486 0.129 −1.979 19.636 0.127 88 −1.984 19.570 0.130 −1.957 19.730 0.128 89 −1.956 19.654 0.131 −1.932 19.825 0.130 90 −1.929 19.738 0.132 −1.905 19.920 0.131 91 −1.900 19.824 0.133 −1.877 20.016 0.133 92 −1.872 19.909 0.134 −1.847 20.113 0.134 93 −1.843 19.996 0.135 −1.816 20.209 0.135 94 −1.814 20.083 0.136 −1.783 20.307 0.137 95 −1.785 20.170 0.137 −1.748 20.405 0.138 96 −1.755 20.258 0.138 −1.713 20.504 0.139 97 −1.726 20.347 0.139 −1.676 20.604 0.141 98 −1.697 20.436 0.140 −1.639 20.704 0.142 99 −1.668 20.525 0.141 −1.601 20.806 0.143 100 −1.639 20.615 0.142 −1.562 20.908 0.144 101 −1.611 20.706 0.143 −1.523 21.010 0.145 102 −1.582 20.797 0.144 −1.483 21.114 0.146 103 −1.555 20.889 0.145 −1.443 21.219 0.148 104 −1.527 20.982 0.146 −1.403 21.324 0.149 105 −1.500 21.076 0.147 −1.363 21.429 0.150 106 −1.473 21.170 0.148 −1.323 21.535 0.151 107 −1.447 21.264 0.149 −1.285 21.641 0.151 108 −1.421 21.360 0.150 −1.247 21.746 0.152 109 −1.395 21.456 0.150 −1.210 21.851 0.153 110 −1.370 21.552 0.151 −1.175 21.955 0.154 111 −1.346 21.650 0.152 −1.141 22.059 0.155 112 −1.322 21.747 0.153 −1.109 22.162 0.155 113 −1.298 21.845 0.154 −1.078 22.265 0.156 114 −1.275 21.944 0.154 −1.049 22.368 0.157 115 −1.253 22.043 0.155 −1.022 22.471 0.157 116 −1.231 22.142 0.156 −0.996 22.574 0.158 117 −1.209 22.241 0.156 −0.972 22.676 0.158 118 −1.189 22.340 0.157 −0.950 22.778 0.159 119 −1.168 22.439 0.158 −0.929 22.880 0.159 120 −1.149 22.538 0.158 −0.910 22.982 0.160 121 −1.130 22.637 0.159 −0.893 23.083 0.160 122 −1.111 22.736 0.159 −0.877 23.184 0.161 123 −1.093 22.835 0.160 −0.863 23.285 0.161 124 −1.075 22.933 0.160 −0.850 23.385 0.162 125 −1.058 23.032 0.161 −0.838 23.486 0.162 126 −1.042 23.130 0.161 −0.828 23.585 0.162 127 −1.026 23.229 0.162 −0.819 23.685 0.162 128 −1.010 23.327 0.162 −0.811 23.784 0.163 129 −0.995 23.426 0.163 −0.805 23.882 0.163 130 −0.980 23.524 0.163 −0.799 23.980 0.163 131 −0.966 23.622 0.164 −0.795 24.077 0.163 132 −0.952 23.720 0.164 −0.792 24.174 0.163 133 −0.939 23.818 0.164 −0.791 24.270 0.163 134 −0.927 23.917 0.164 −0.791 24.364 0.163 135 −0.915 24.014 0.165 −0.792 24.458 0.163 136 −0.904 24.112 0.165 −0.794 24.551 0.162 137 −0.893 24.210 0.165 −0.798 24.642 0.162 138 −0.882 24.308 0.165 −0.803 24.733 0.162 139 −0.873 24.406 0.165 −0.809 24.822 0.162 140 −0.864 24.504 0.166 −0.816 24.910 0.162 141 −0.855 24.602 0.166 −0.824 24.996 0.161 142 −0.847 24.700 0.166 −0.834 25.081 0.161 143 −0.840 24.799 0.166 −0.844 25.165 0.161 144 −0.833 24.898 0.166 −0.856 25.246 0.160 145 −0.827 24.997 0.166 −0.868 25.326 0.160 146 −0.821 25.097 0.165 −0.881 25.405 0.160 147 −0.816 25.197 0.165 −0.894 25.482 0.159 148 −0.811 25.297 0.365 −0.908 25.557 0.159 149 −0.807 25.398 0.165 −0.923 25.630 0.158 150 −0.804 25.499 0.165 −0.937 25.702 0.158 151 −0.801 25.600 0.165 −0.952 25.772 0.158 152 −0.798 25.702 0.164 −0.966 25.840 0.157 153 −0.796 25.804 0.164 −0.981 25.907 0.157 154 −0.795 25.906 0.164 −0.995 25.973 0.156 155 −0.794 26.008 0.163 −1.010 26.038 0.156 156 −0.793 26.111 0.163 −1.024 26.102 0.156 157 −0.793 26.214 0.163 −1.038 26.166 0.155 158 −0.794 26.316 0.162 −1.052 26.229 0.155 159 −0.794 26.419 0.162 −1.066 26.291 0.155 160 −0.796 26.521 0.161 −1.079 26.352 0.154 161 −0.797 26.624 0.161 −1.092 26.412 0.154 162 −0.799 26.726 0.160 −1.105 26.471 0.153 163 −0.801 26.829 0.160 −1.117 26.528 0.153 164 −0.804 26.931 0.159 −1.128 26.583 0.153 165 −0.807 27.032 0.159 −1.139 26.637 0.152 166 −0.811 27.134 0.158 −1.149 26.690 0.152 167 −0.814 27.235 0.158 −1.159 26.740 0.152 168 −0.819 27.336 0.157 −1.168 26.789 0.152 169 −0.823 27.437 0.157 −1.177 26.835 0.151 170 −0.828 27.537 0.156 −1.185 26.879 0.151 171 −0.833 27.637 0.156 −1.192 26.921 0.151 172 −0.838 27.736 0.155 −1.199 26.961 0.151 173 −0.844 27.835 0.155 −1.205 26.999 0.150 174 −0.849 27.933 0.154 −1.211 27.035 0.150 175 −0.855 28.030 0.154 −1.216 27.069 0.150 176 −0.862 28.127 0.153 −1.221 27.101 0.150 177 −0.868 28.222 0.152 −1.226 27.131 0.150 178 −0.874 28.317 0.152 −1.230 27.159 0.150 179 −0.881 28.410 0.151 −1.234 27.186 0.150 180 −0.887 28.503 0.151 −1.238 27.212 0.149 181 −0.894 28.594 0.150 −1.241 27.236 0.149 182 −0.901 28.685 0.149 −1.245 27.259 0.149 183 −0.908 28.775 0.149 −1.248 27.280 0.149 184 −0.915 28.863 0.148 −1.251 27.301 0.149 185 −0.922 28.950 0.148 −1.253 27.321 0.149 186 −0.929 29.037 0.147 −1.256 27.339 0.149 187 −0.936 29.122 0.146 −1.258 27.357 0.149 188 −0.943 29.206 0.146 −1.261 27.374 0.149 189 −0.949 29.289 0.145 −1.263 27.391 0.149 190 −0.956 29.370 0.145 −1.265 27.408 0.149 191 −0.963 29.450 0.144 −1.267 27.424 0.149 192 −0.970 29.529 0.143 −1.269 27.441 0.149 193 −0.977 29.607 0.143 −1.271 27.458 0.149 194 −0.984 29.683 0.142 −1.273 27.475 0.149 195 −0.990 29.757 0.142 −1.276 27.493 0.149 196 −0.997 29.831 0.141 −1.278 27.512 0.149 197 −1.004 29.902 0.141 −1.280 27.532 0.149 198 −1.010 29.973 0.140 −1.283 27.553 0.149 199 −1.016 30.042 0.140 −1.286 27.577 0.149 200 −1.023 30.110 0.139 −1.289 27.602 0.149 201 −1.029 30.176 0.139 −1.292 27.628 0.149 202 −1.035 30.242 0.138 −1.295 27.656 0.149 203 −1.041 30.306 0.138 −1.298 27.686 0.149 204 −1.047 30.369 0.137 −1.302 27.718 0.149 205 −1.053 30.432 0.137 −1.305 27.751 0.149 206 −1.059 30.494 0.136 −1.309 27.787 0.149 207 −1.065 30.555 0.136 −1.313 27.824 0.149 208 −1.071 30.615 0.136 −1.317 27.863 0.149 209 −1.076 30.675 0.135 −1.321 27.903 0.149 210 −1.082 30.734 0.135 −1.325 27.945 0.149 211 −1.088 30.793 0.134 −1.329 27.988 0.149 212 −1.093 30.851 0.134 −1.334 28.032 0.149 213 −1.099 30.909 0.133 −1.338 28.078 0.149 214 −1.105 30.966 0.133 −1.342 28.125 0.149 215 −1.110 31.023 0.133 −1.346 28.173 0.150 216 −1.116 31.079 0.132 −1.351 28.222 0.150 217 −1.121 31.135 0.132 −1.355 28.273 0.150 218 −1.126 31.190 0.131 −1.360 28.325 0.150 219 −1.131 31.245 0.131 −1.365 28.377 0.150 220 −1.136 31.300 0.130 −1.369 28.429 0.150 221 −1.142 31.355 0.130 −1.374 28.481 0.150 222 −1.147 31.409 0.130 −1.378 28.533 0.150

Example 4

This example illustrates z scores obtained using LMS for measurements other than MUAC for children up to 55 weeks of post menstrual age (gestational age plus chronological age). In generating the data detailed in Table 3, it was determined that the circumferences of the middle thigh (MTC), chest (CC), and abdomen (AC), when measured as described above, are strongly correlated with weight. The correlation coefficients are as follows: weight r2: 0.93, 0.95, 0.90 for MTC, CC and AC, respectively; height r2: 0.85, 0.89, 0.91 for MTC, CC and AC, respectively.

TABLE 3 Mid Thigh circumference (males and females combined) Post menstrual age (weeks) L M S 27 −1.12547 7.322662 0.104284 28 −1.00891 7.890045 0.104426 29 −0.89236 8.458449 0.104569 30 −0.7758 9.028895 0.104711 31 −0.65847 9.606316 0.104855 32 −0.54047 10.19141 0.104999 33 −0.42197 10.78314 0.105144 34 −0.30359 11.37527 0.105288 35 −0.18599 11.96189 0.105432 36 −7.00E−02 12.53576 0.105574 37  4.39E−02 13.09172 0.105713 38 0.155975 13.6356 0.10585 39 0.266923 14.17306 0.105986 40 0.375951 14.69621 0.106119 41 0.483568 15.20906 0.106251 42 0.591414 15.72587 0.106383 43 0.700559 16.25612 0.106516 44 0.811265 16.80256 0.106652 45 0.922443 17.35506 0.106787 46 1.033073 17.90412 0.106923 47 1.14246 18.44349 0.107056 48 1.249745 18.96552 0.107188 49 1.354107 19.46322 0.107315 50 1.455709 19.93855 0.107439 51 1.555527 20.39988 0.107561 52 1.654644 20.85594 0.107683 53 1.753637 21.31117 0.107804 54 1.852676 21.76685 0.107925 55 1.951738 22.22273 0.108046

TABLE 4 Chest Circumference (males and females combined) Post menstrual age (weeks) L M S 27 0.464466 19.82165 6.84E−02 28 0.444882 20.77386 6 80E−02 29 0.425297 21.72951 6.75E−02 30 0.405713 22.69205 0.06711 31 0.385962 23.67329 6.67E−02 32 0.366071 24.67588 0.06626 33 0.346031 25.70185 6.58E−02 34 0.325892 26.7451 6.54E−02 35 0.30573 27.79745  0.064967 36 0.285641 28.85031 6.45E−02 37 0.265763 29.89229 6.41E−02 38 0.246211 30.9202 6.37E−02 39 0.227227 31.91376 6.33E−02 40 0.209038 32.85575 6.29E−02 41 0.191728 33.74672 6.25E−02 42 0.175324 34.58977 6.22E−02 43 0.159873 35.3818 6.18E−02 44 0.145401 36.1197 6.15E−02 45 0.131979 36.79626 6.12E−02 46 0.119594 37.41171 6.10E−02 47 0.108161 37.97224 6.07E−02 48 9.76E−02 38.4839 6.05E−02 49 8.77E−02 38.95449 6.03E−02 50 7.84E−02 39.39504 6.01E−02 51 6.95E−02 39.81699 5.99E−02 52 6.07E−02 40.2298 5.97E−02 53 5.20E−02 40.64092 5.95E−02 54 4.32E−02 41.05242 5.93E−02 55 3.45E−02 41.46424 5.91E−02

TABLE 5 Abdominal Circumference (males and females combined) Post menstrual age (weeks) L M S 27 0.411093 20.58405 7.15E−02 28 0.426755 21.55277 7.18E−02 29 0.442417 22.527 7.21E−02 30 0.458079 23.51225 7.23E−02 31 0.473845 24.51841 7.26E−02 32 0.489575 25.53 0.072934 33 0.505089 26.52107 7.32E−02 34 0.520115 27.45283 0.073506 35 0.534478 28.30728 7.38E−02 36 0.548151 29.0887 7.40E−02 37 0.561281 29.81715 7.43E−02 38 0.574498 30.56576 0.074525 39 0.587988 31.35169 7.48E−02 40 0.60162 32.15553 7.50E−02 41 0.615375 32.97901 7.53E−02 42 0.629005 33.79831 0.075546 43 0.642322 34.60039 7.58E−02 44 0.655111 35.36763 7.60E−02 45 0.66717 36.08266 7.63E−02 46 0.678331 36.73132 7.65E−02 47 0.688655 37.32224 7.67E−02 48 0.698164 37.85835 7.68E−02 49 0.706831 38.33796 7.70E−02 50 0.714702 38.76521 0.077151 51 0.721965 39.15374 7.73E−02 52 0.728902 39.52201 7.74E−02 53 0.735766 39.88597 7.75E−02 54 0.742679 40.25312 7.77E−02 55 0.749624 40.6223 7.78E−02

Example 5

This example illustrates z scores obtained using LMS for MUAC measurements for children up to 55 weeks of post menstrual age (gestational age plus chronological age).

TABLE 6 Age L M S 27 −1.50705 5.204456 9.60E−02 28 −1.36221 5.54182 9.68E−02 29 −1.21738 5.8828 9.75E−02 30 −1.07254 6.231014 9.82E−02 31 −0.92422 6.59941 9.90E−02 32 −0.77259 6.994292 9.98E−02 33 −0.61727 7.41864 0.100547 34 −0.459 7.865008 0.101345 35 −0.29823 8.331139 0.102254 36 −0.13656 8.808112 0.103234 37 2.34E−02 9.283344 0.103983 38 0.178288 9.744143 0.10409  39 0.324063 10.16997 0.103327 40 0.456342 10.53853 0.101877 41 0.575261 10.85917 0.100182 42 0.683784 11.14999 0.098453 43 0.786568 11.43184 9.67E−02 44 0.885746 11.71175 9.50E−02 45 0.980038 11.98133 9.35E−02 46 1.066813 12.2275 9.21E−02 47 1.145699 12.44839 9.08E−02 48 1.216893 12.645 8.97E−02 49 1.280363 12.81768 0.088806 50 1.33682 12.96927 8.80E−02 51 1.38849 13.10688 8.72E−02 52 1.438082 13.23855 8.65E−02 53 1.487393 13.36943 8.58E−02 54 1.536883 13.50085 8.51E−02 55 1.5865 13.63263 8.43E−02 

1. An electronic apparatus for estimating the nutritional status of an individual, said apparatus comprising: a measurement device configured to measure a circumference of a body part of an individual and provide a first measurement value; a user interface configured to receive user input of the age and gender of the individual to be measured; a memory configured to store a plurality of age- and gender-specific standard score values, each of said plurality of standard score values corresponding to a circumference measurement value of a body part for a designated age and gender and indicating nutritional status ranges at, above, or below a nutritional norm for the designated age and gender; and a processor operatively connected with said memory and configured to determine a standard score value for the individual, wherein said first measurement value corresponds to a standard score value that estimates the nutritional status of the individual for said designated age and gender when the measurement device is used to measure the circumference of the body part of the individual.
 2. The electronic apparatus of claim 1, wherein said processor is configured to execute machine readable instructions that cause the processor to: store, in the memory, the user input of the age and gender of the individual to be measured; store, in the memory, the first measurement value of the individual when the measurement device is used to measure the circumference of the body part of the individual; and compare the first measurement value to the plurality of age- and gender-specific standard score values; and estimate the nutritional status of the individual.
 3. The electronic apparatus of claim 1, wherein said user interface is configured to display the nutritional status of the individual for the user.
 4. The electronic apparatus of claim 1, wherein said processor is configured to execute machine readable instructions that cause the processor to: store, in the memory, the user input of the age and gender of the individual to be measured; store, in the memory, the first measurement value of the individual when the measurement device is used to measure the circumference of the body part of the individual; and calculate, with reference to the plurality of age- and gender-specific standard score values, a z-score value for said individual, wherein said z-score value is displayed on said user interface.
 5. The electronic apparatus of claim 4, further configured to display a deviation of said z-score value from the nutritional norm.
 6. The electronic apparatus of claim 4, wherein said z-score is calculated from lambda, mu, and sigma values that derive from population data for designated ages and genders.
 7. The electronic apparatus of claim 1, wherein the nutritional status of the individual is displayed on said user interface as a number, letter, color, or symbol.
 8. The electronic apparatus of claim 1, wherein the measurement device electronically measures the circumference of the body part.
 9. The electronic apparatus of claim 8, wherein the electronic apparatus comprises a wheel, ball, roller, or laser, wherein said measurement device is configured to record a distance traveled by said wheel, ball, roller, or laser moved about the circumference of the body part to provide said first measurement value.
 10. The electronic apparatus of claim 1, further comprising a measuring tape or cord configured to be wrapped about the circumference of the body part, wherein said measurement device records a length of said measuring tape or cord wrapped around the body part to provide said first measurement value.
 11. A method of estimating the nutritional status of an individual, said method comprising the steps of: measuring the circumference of a body part of an individual using an electronic apparatus according to claim 1 to provide a first measurement value; entering the age and gender of the individual in the user interface; and obtaining the nutritional status of the individual from the user interface based upon the first measurement value.
 12. The method of claim 11, wherein the measurement device electronically measures the circumference of the body part.
 13. The method of claim 11, wherein the electronic apparatus comprises a wheel, roller, ball, or laser, wherein said circumference is measured by positioning the wheel, roller, ball, or laser on the skin of the body part and moving it about the circumference of the body part.
 14. The method of claim 11, wherein the electronic apparatus comprises a measuring tape or cord configured to be wrapped about the circumference of the body part to be measured, wherein said measurement device records a length of said measuring tape or cord wrapped around the body part to provide said first measurement value.
 15. The method of claim 14, further comprising the step of positioning the measuring tape or cord up around the body part, and retracting the measuring tape or cord up against the body part to provide the first measurement value.
 16. The method of claim 11, said user interface displaying said first measurement value after measuring the circumference of the body party of the individual.
 17. The method of claim 11, wherein the nutritional status of the individual is displayed on said user interface as a number, letter, color, or symbol.
 18. The method of claim 11, wherein said processor is configured to execute machine readable instructions that cause the processor to: store, in the memory, the first measurement value of the individual after measuring the circumference of the body part of the individual; store, in the memory, the age and gender of the individual entered into the user interface; and calculate, with reference to the plurality of age- and gender-specific standard score values, a z-score value for said individual, wherein said z-score value is displayed on said user interface.
 19. The method of claim 18, said user interface displaying a deviation of said z-score value from the nutritional norm.
 20. The method of claim 18, wherein said z-score is calculated from lambda, mu, and sigma values that derive from population data for designated ages and genders. 